Understanding the individual responsiveness to resistance training periodization

Area of Science:

• Exercise Physiology
• Gerontology
• Biochemistry

Background:

• Resistance training (RT) is crucial for maintaining functional capacity in elderly sedentary women.
• Periodization models, such as linear periodization (LP) and undulating periodization (UP), are used to optimize RT.
• Individual variability in response to RT, particularly concerning biomarkers, is not well understood in this population.

Purpose of the Study:

• To compare the effects of LP and UP on functional capacity, neuromuscular function, body composition, and cytokines in elderly sedentary women.
• To identify high, medium, and low responders (HR, MR, LR) for specific biomarkers (irisin, IL-1β, TLR-4, BDNF) following RT.
• To investigate the impact of different periodization strategies on these individual response patterns.

Main Methods:

• Forty-nine elderly women were divided into a control group, an LP group, and a UP group.
• Evaluations included functional capacity tests (e.g., chair-stand, TUG), maximal strength (leg press 1RM), body composition, and serum levels of irisin, IL-1β, TLR-4, and BDNF.
• Statistical analyses were performed to compare changes between groups and identify responder categories.

Main Results:

• Both LP and UP significantly improved functional capacity and maximal strength compared to the control group.
• No significant differences were observed in body composition or cytokine levels between the LP and UP groups.
• Individual responder categories (HR, MR, LR) were identified for irisin, IL-1β, TLR-4, and BDNF, with variations across groups and time points.

Conclusions:

• Both LP and UP are effective in enhancing functional capacity and neuromuscular function in elderly sedentary women.
• The lack of significant changes in body composition and cytokines may be attributed to the diverse individual responsiveness to RT.
• This study provides novel insights into individual biomarker responses (irisin, IL-1β, TLR-4, BDNF) to RT in older adults, highlighting the concept of responders and non-responders.